A device commonly referred to as a power converter is often used in electrical systems and/or power electronic systems. The power converter may receive electrical power from an electrical power source, condition the electrical power, and supply the conditioned electrical power to one or more electrically powered devices. During use, the power converter may generate undesired heat. Dissipating the heat generated by the power converter may improve an efficiency thereof and may limit premature damage and/or degradation of components thereof.
In one situation, the power converter may employ an air cooling system, such as a fan based cooling system, in order to direct cooling air over the components thereof to dissipate the generated heat. However, the air cooling system may have a lower cooling efficiency and may require high air flow rates for achieving a desired heat dissipation rate. Also, the air cooling system may be impractical in some environments, such as, a dusty environment, a high moisture environment, and/or the like.
In another situation, a fluid cooling system may be employed such that a coolant may be circulated through or past a heat sink. The heat sink may be provided in thermal contact with the components of the power converter in order to dissipate the generated heat therefrom. In such a fluid cooling system, the coolant may enter the heat sink at one end thereof and may exit the heat sink at another end thereof. However, during circulation of the coolant through the heat sink, the coolant may collect heat and may attain a higher temperature much before exiting the heat sink.
For example, the coolant having a low temperature may enter the heat sink and during circulation thereof within the heat sink, the coolant may attain the high temperature within an initial portion or around a mid-portion of the heat sink. As a result, the coolant may continue to be circulated with the high temperature through a remaining or latter portion of the heat sink. In such a situation, the heat sink and the power converter may experience an undesired thermal gradient during use.
The thermal gradient may result in premature failure of the components of the power converter, overheating of the junction due to poor current sharing, failure due to loss of gate control, premature wear out due to expansion fatigue, and/or the like. Also, the fluid cooling system may present various mechanical and structural challenges related to packaging of the components compactly while still allowing for a required heat dissipation rate. Hence, there is a need for an improved heat transfer mechanism for such electrical components and systems.
U.S. Pat. No. 9,279,625 describes a heat sink for power modules of a machine. The heat sink includes a body having a plurality of divider webs integral thereto and defining a plurality of longitudinal passage segments within the body. The body is machined to remove alternating end portions of the divider webs to define a fitting end turn area and a return end turn area disposed in opposing relationship with each other, thereby forming a serpentine fluid passage. A fitting end cap is welded to the body. A fluid inlet and a fluid outlet of the fitting end cap are respectively in fluid communication with a passage inlet and a passage outlet of the serpentine fluid passage.